2.0 Analysis 2.1 The Approach The aircraft was operating in below freezing temperatures, with snow and blowing snow conditions on the ground at both the departure and the arrival airports. The aircraft was radar-vectored in a routine manner. The crew flew a stabilized straight-in ILS approach at the appropriate altitudes and airspeeds. The aircraft was in the correct landing configuration and at the appropriate airspeed when it touched down on the threshold, at or near the runway centre line. 2.2 Main Landing Gear Wheels 2.2.1 Left Landing Gear The rapid rate at which the nose of the aircraft dropped after the main landing gear wheels contacted the runway, the continuous black scuff mark along the runway surface from near the point of touchdown, and the flat spots worn on both tires of the dual wheel left landing gear, all indicate that the left main landing gear wheels did not rotate from the time the aircraft landed until it went off the runway into the snow. The left main landing gear wheels would not rotate when maintenance crews attempted to tow the aircraft back onto the runway. However, applying heat to the brake assembly for several minutes allowed the wheels to rotate freely, indicating that the brakes were frozen and caused the wheel to bind. No other discrepancies were found with the left wheels or brake assembly. As there are no means to prevent blowing snow from entering the brake disk area, it is likely that, during the departure from Sudbury, snow had blown onto the warm brake surfaces, melted, and then frozen either en route to North Bay or when the crew lowered the landing gear in the cold slipstream prior to landing. 2.2.2 Right Landing Gear There was no evidence of binding or discrepancies found with the right main landing gear wheel or brake assembly. The crew reported heavy application of the right brake when the aircraft veered to the left on the landing roll. However, there was no evidence either on the right tires or on the runway surface to indicate brake activation on the right side during the landing roll. It was not determined why the right brake appeared not to function during the landing roll. 2.3 Loss of Directional Control The left main wheels were frozen and did not rotate during the landing roll, leading to loss of directional control of the aircraft on the ground. 3.0 Conclusions 3.1 Findings The aircraft was operating in below freezing temperatures with snow and blowing snow conditions on the ground at the departure and arrival airports. The aircraft left main landing gear brake froze, preventing the left wheels from rotating during the landing roll. It was not determined why the right brake appeared not to function during the landing roll. Directional control of the aircraft was lost during the ground roll, and the aircraft went off the left side of the runway. The flight crew was certified and qualified for the flight in accordance with existing regulations. The aircraft was certified, equipped, and maintained in accordance with existing regulations and approved procedures. 3.2 Causes A frozen left brake prevented the left wheels from rotating during the landing roll. Directional control of the aircraft was lost during the ground roll, and the aircraft went off the left side of the runway. The Board has no aviation safety recommendations to issue at this time.4.0 Safety Action The Board has no aviation safety recommendations to issue at this time.